Climate cenarios 2026

We aimed to investigate how tree seedlings respond to a future climate scenario 1176 simulated in growth chambers (phytotrons). We selected four widely distributed tree species from the Cerrado savanna: Qualea grandiflora (Vochysiaceae), Hymenaea stignocarpa (Fabaceae), Tabebuia aurea (Bignoniaceae) and Kielmeyera coriacea (Clusiaceae). We disposed their seeds to germinate in chambers at 28°C, and then raised the seedlings in pots filled with Red Latosol and sand (proportion of 3x1) under irrigation at 28 °C for 30 days. After that, we transferred the seedlings to plastic tubes of 1m high and of 0.1 m in diameter for the growth experiments. When the first pair of leaves appeared, 30 individuals of each species were taken for initial measures, and other 33 individuals were transferred to each phytotron, summing up a total of 96 plants per species. One of the phytotrons was set with the current climate scenario, based on the last 50 years climate data from the Cerrado where max and min temperatures was 28 °C and 18 °C, and CO2 concentration ([CO2]) was 420 ppm. The other phytotron was set with the IPCC SSP 3-7,0 prospection for the Cerrado region for 2100 (WorldClim), where max and min temperatures reached 2.5 °C higher than at current climate scenario, and [CO2] was 860 ppm. Humidity was 85 % for both phytotrons. Plants were grown for 120 days, being irrigated every two days with 120 ml of tap water. After this period, we proceeded with leaf counting of the individuals and then all plants were uprooted and taken to dry at 70 °C. After drying, plants biomass was measured by parts: total, root, shoot, and leaves.

本研究旨在探究木本幼苗对生长箱（人工气候室，phytotron）中模拟的1176号未来气候情景的响应。我们从巴西塞拉多稀树草原中选取了4种广布木本植物：Qualea grandiflora（楔瓣花科，Vochysiaceae）、Hymenaea stignocarpa（豆科，Fabaceae）、Tabebuia aurea（紫葳科，Bignoniaceae）以及Kielmeyera coriacea（藤黄科，Clusiaceae）。我们将各物种的种子置于28℃的培养箱中催芽，随后将萌发的幼苗移栽至装有红色砖红壤（Red Latosol）与沙子按3:1比例混合的基质的花盆中，在28℃的灌溉条件下培养30天。之后，我们将幼苗移栽至高1m、直径0.1m的塑料管中以开展生长实验。当幼苗长出第一对真叶时，我们选取每个物种的30株个体进行初始性状测定，剩余的33株个体则分别移栽至两台人工气候室中，最终每个物种共计96株试验植株。其中一台人工气候室设置为当前气候情景，其参数基于塞拉多地区近50年的气候数据：最高气温28℃、最低气温18℃，二氧化碳浓度（[CO2]）为420 ppm。另一台人工气候室则设置为IPCC发布的塞拉多地区2100年SSP3-7.0情景（WorldClim数据集）下的未来气候情景：最高与最低气温较当前情景分别升高2.5℃，二氧化碳浓度为860 ppm。两台人工气候室的相对湿度均设置为85%。试验植株均培养120天，每两天用120ml自来水灌溉一次。培养期满后，我们先统计各植株的叶片数量，随后将所有植株连根拔起，置于70℃环境中烘干至恒重。烘干完成后，我们将植株按组分分别测定生物量：总生物量、根生物量、地上部生物量以及叶生物量。